The present invention relates generally to a gas-dust removing filter apparatus having filter tubes or bags arranged to be cleaned by counterflow scavenging, and particularly to seals for such filter tubes or bags at the clean gas side of a perforated partition which subdivides a casing, of the gas-dust removing filter apparatus, into a dust-removing chamber and a clean gas chamber. The seal is of the kind including a clamping frame to grip the rim of the open mouth of a filter tube or bag in resilient manner between itself and the partition. The filter tubes or bags are inserted into the dust removing chamber via the perforations of the partition, and are provided each with a rigid internal spacing element. When the partition is in a vertical plane, the filter tubes or bags are supported in a horizontal position by having their free ends supported at the rear wall of the casing. The partition may also be disposed in a horizontal plane in the casing, and in such an embodiment, the filter tubes or bags may be suspended vertically from the horizontal partition. A conventional seal of the kind described above is illustrated in German Pat. Application No. P 29 32 521.1. This disclosure teaches a clamping frame for gripping the rim of a filter tube mouth which is connected to a tension spring acting on the rim of the tube when placed under stress. The other end of the spring is firmly connected to a spacing element disposed inside the filter tube and supporting the same. The effect of this arrangement is to have the spacing element bearing, via a bridge element, on the inner side of the peripheral rim of a perforation in the partition.
It is an object of the invention to simplify the resilient seal of the rim of the filter tube mouth at the clean gas side of the perforated partition and, at the same time, to prevent or minimize the risk of the spacing elements of the filter tubes being carried into the partition holes via the tube material and causing damage to the tubes.